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Processes of high-energy ball milling of SmCo 5 alloys were compared for three single-liquid environments without using additional surfactants. Both coarsely grained as-cast and nanocrystalline pre-milled SmCo 5 precursors showed tendency toward formation of thin flakes if milled in polar liquids (acetone and ethanol) in a marked contrast to milling in non-polar heptane. CaF 2 dielectric powder added prior to milling in the polar liquids tends to become attached on the flake surfaces. Milling in heptane in the presence of CaF 2 produces flake-like SmCo 5 particles which with increasing the milling time are found to incorporate an increasing amount of CaF 2 . The SmCo 5 —5 wt% CaF 2 mixtures milled for the optimum time in both the polar and non-polar liquids were successfully hot-pressed into laminated composite magnets having intrinsic coercivity of 25–30 kOe, maximum energy product of approximately 6.5 MG Oe and electrical resistivity of 500–600 μΩ cm, which is more than 7 times the resistivity of conventional Sm–Co magnets.

We report the fabrication of planar microstripline reciprocal phase shifter using a bulk Yttrium Iron Garnet (YIG) material. The propagation direction of the microstripline and magnetization direction of the YIG is collinear, and the length of the microstripline and the YIG was 50 mm in length. The proposed design shows large differential phase shifts of 100 degrees for applied magnetic fields varying from 0 to 0.56 times 104 A/m over the frequency range of 1.2 GHz between 5.4 GHz and 6.6 GHz. The average insertion loss, ~ 2.5 dB, was measured to have a 20% bandwidth at 6 GHz. The planar phase shifter presented here demonstrates a compact design, low loss, and an especially large phase shift with a relatively small bias field.

Sc is substituted for Fe in Ba M-type hexaferrite to reduce the anisotropy field and shift the ferromagnetic resonance (FMR) frequency to below 20 GHz. We have produced pure phase BaFe11 ScO19 powders having a platelet microstructure. These materials are pressed under an applied magnetic field of 95.5times10 5 A/m. Resulting compacts are sintered and are shown to have a clear uniaxial anisotropy with the c-axis perpendicular to the surface plane. Hysteresis loops display a squareness of 0.83 with a coercivity of ~186 kA/m. The X-band FMR power derivative linewidth is measured to be 79.6 kA/m